OECD 117 – Partition Coefficient, HPLC Method

OECD 117 assesses the Partition Coefficient of a material by High Performance Liquid Chromatography (HPLC).

OECD 117 is an important assessment that determines a chemical’s partition coefficient, which can be utilized for many testing purposes and industries.

The partition coefficient is the ratio of the equilibrium concentrations of a dissolved substance in a two-phase system consisting of two largely immiscible solvents. The partition coefficient is ultimately a measure of the difference in solubility of the two immiscible phases. Furthermore, the partition coefficient determines how hydrophobic or hydrophilic the chemical substance is.

The hydrophobicity of a compound can assist in an analysis to determine how easily a compound may be absorbed into and mobilize in groundwater, causing polluted waterways. It can also help evaluate a chemical’s toxicity to animals and aquatic life. Performing OECD 117 and knowing a chemical’s partition coefficient is commonly recommended for performing Toxicology tests, such as OECD 201, OECD 202, and OECD 203.

Additionally, the ability to determine a chemical’s partition coefficient benefits the medical industry by determining how quickly a drug distributes throughout the body. For example, hydrophobic drugs with high octanol/water partition coefficients are generally distributed to hydrophobic areas such as a cell’s lipid bilayers. The opposite is seen with hydrophilic drugs that have low octanol/water partition coefficients and are found primarily in aqueous areas of the body such as blood serum.

There are two standard OECD test methods used to assess the Partition Coefficient of a material.

Partition coefficients with values in the range -2 to 4 (occasionally up to 5 and more) can be experimentally determined by the Shake-Flask method (OECD 107)